Screw jack



sept. 27, 1932. w C, TYLER 1,879,999

scREw JACK Filed Oct. 1. 1931 5 Sheets-Shea?.l l .12051. j

Mx r- 1999999191919@ sept. 2 7, 1932. w. Q TYLER 1,879,999

SCREW JACK Filed Oct. l. 1931 5 Sheets-Sheet 2 jwefafor: 9

Sept. 27, 1932.

W. C. 'TYLER scREw JACK Filed oct. 1, 1931 3 Sheets-Sheet 5 Patented Sept. 27, 1932 invasie rais WILLIAM C. TYLER, OF JULIET, ILLINOIS, ASSIGNOR TO WILLIAM E. PRATT MFG. O0.,

OF J OLIET, ILLINOIS, A CORPORATION OF ILLINOIS SCREW JACK Application filed October l, 1931. Serial'No. 566,326.

This invention relates to screw jacks `and` more particularly to screw jacks of the double-lift type.

One of the objects of the invention is to J' provide a screw jack of simple and staunch construction which is designed to be col-` lapsed into a. compact unit occupying a minimum of space and whichmay be extended to the desired height for `lifting automo# J0 biles and the like. Another obJect is to provide a new jack construction in which many of the working parts are housed in such al 2, a top plan view; 3 a vertical sectional view, the section being taken as indicatedv at line 3 of Fig. 2; Fig.l A, a broken plan sectional view,'the section being taken as indiview similar to the sectional view shown in Fig. 3, but showing the lifting members in partially extended position; Fig. 6, a broken sectional view of a modified form of jack em'- bodying my invention; Fig. 7, a transverse sectional view; the section being taken as indicated at line 'l' of Fig. 6; Fig. 8, a sectional view of parts within the casing, the section being taken as indicated at line S of F ig. 6; Fig. 9; a plan view ofthe locking washer employed; and Fig. 10, a sectional view of the casing employed with the modified form of screw jack. p

In the illustration given in Figs. 1 to 5, A

with a. base A and a bore A2. The casing is also provided with the usual extension A3 in l which the actua-ting shaft'l is rotatably supported. The shaft is provided with a bevel gear member 2.

As illustrated more clearly in Fig. 3; a tubular extension 3 is provided at the top of the casing A and carries a drive nut A. The

drive nut A is confined between member 8 and the casing extension A8. VDrive nut A is cene this prevents-the held upside down. cated at line 41 of Fig. 3; Fig. 5, a sectional designates a jack casing which is provided' trally apertured and is provided with a key;

A sleeve lifting member 6 extends through the drive nut 5 and is provided with a groove 7 which engages the key 5 of nut t. The" sleeve member 6 is vprovided withan upper internally threaded nut8 and with'a lower internally threaded nut 9. An inner lifting screw 10 engages the upper nut 8. AA rotatable screw post 11 engages the lower nut 9 of the sleeve member 6. The screw post 11 is preferably provided witlia'reduced square end 12 which extends through a square opening lin a circular plate 13. The'plate or disk 13 is preferably providedV at its periphery with a circular groove 14, which is provided with frictionv indentations or projections lili.'v as illustrated.

The base A of the casing, in Fig. 3, is provided with a plunger coin-V partment 15 in which a spring urged plunger 16 is reciprocally guided' The plunger 16 is provided with a rounded end which en-V gages the circular groovel 14 of disk 13;

The screw post 11 is provided at vits upper end with a stop pin 17 which is adapted to engage the nut 9 and tol lock post 11 -to sleeve 6.

In the operation of the ack, with the parts in collapsed position, as shown in Fig. 3, the

rotation of drive nut i in one direction causes Jthe sleeve 6 to rotate therewith. The screw post 11 being frictionally held against rotation by plunger 16 which engages disk 13,

causes sleeve 6 to rise, thevrotat-ing nut 9 en V `gaging the threads of the temporarily fixed post 11. As the sleeve 6 rises; it carries the inner screw 10 bodily with it. lVhen Vthe sleeve 6 has reached the upperlimit of its travel; the pin 17 vengages nut 9,-and locks the post 11 to sleeve 6. Continuedrotation of nut 5 causes sleeve6 and the screw post11` jack f from vextending when in Figs. 6 to 10, B represents a hollow jackv casing provided with a base B and an upper ,casing extension B2. The upper' Vcasing extension B2 rotatively supports Aa drive rod 1 which is equipped with a bevel gear 2. collar 3 is carried by casing B and supportsY in turn drive nut 4. VDrive nut4his centrally apertured and is provided interiorly' with a key 5.

The casing B` is provided with a vertical j groove 18 which opens into an enlarged chamber 19 at the top of the casing and into a similar large chamber 2O at the bottom ofV the casing. The groove 18 is 'provided withV oppositely disposed curved camv walls 21 and 22 at its upperfa'nd lower ends respectively. 1

A sleeve member 23 extends through drive nut 4 and into the ,bore ofthe jack-casing. On its outer sideit is provided with a groove or keywayY 24 which is engaged by key 5 of drive nut 4. lnteriorly, the sleeve member'23 is equipped with upper and lower drive nuts and is the same in Aconstruction las sleeve member Glieretofore described. An inner lifting screw 25, similar to lifting screw 10,'heretofore described, engages. the upper nut of sleeve 23. A rotatably mounted screw post 26 extends through fthe lower nut of sleeve 23. The screw post 26 is provided witha vertical groove 27 which extends substantially through the lengthv of the post.

As shown more clearly in Fig. 6, sleeve 23 is provided at its `lower end with .a reduced portion 28 which has its lower edge flared outwardly to provide a retaining flange. An annular ring 29 is secured upon the end 28 by the retaining flange and is connected byKV depending lugs30 to a lockingrwasher 31. As shown more clearly in Fig. 9, washer 31 is provided with openings 32 through which lugs 30 extend.V An inwardly turned key 33 4engages the groove k27 of thescrew-post 26. A pair of diametrically disposed lugs 34 engage grooves 18 in the casing B.

Disposed in thel lower compartment` or' chamber 20 of the casing and encircling screw post 26 is a short coil spring 35. The pure pose of the spring is to urge the washer 31 into Contact with the cam wall 22 when the sleeve 23is to be started on its upward rotation of drive nut 4 and sleeve 23 in one l' ydirection causes the sleeve to rise, the inner screw being held against rotation in the following manner. The rotation of the washer washer 31 is provided with an inner key 33 engaging groove 27 ofpost 26, post 26 is also held against rotation. Engagement ofthe Vloweriiut of sleeve 23 withthe temporary fixed post 26 causes the sleeve to rise, bearing with vit the inner screw 25. At the Same time, the

'sleeve 23 carriesv washer 31 by means of the connecting lugs 30 and ring 29. When the sleeve 23 reaches the upper limit of its travel, the washer 31 enters -tlie enlarged chamber V19 and the'lugs 34 slide over cam 21 as the sleeverotates. The sleeve 23 and screw post 26 are now free to rotate together. Assuming that the inner screw 25 has been brought into engagement with the load, continued rotation of the sleeve 23'will cause the upper nut a g5 to drive screw 25 in an upward direction. In returning the screw parts to their collapsed position, the nutV is turned in the opposite direction. The projections 34 engage thek straight wall ofthe groove 18 and prevent further rotation of the washer 31. V"With the screw'post again temporarily locked against rotation, the sleeve 23 descends to its original position, thel washer 31 ventering the lower enlarged chamber 20 and rotating .freely therein. Y Y

In both forms of jacks illustrated, it will be observed that the inner screw post is rotatably mounted and is restrained against rotation during the upward movement of the sleeve members.

the sleeve has reachedthe limits of its travel, at which points the screw is free to rotate in one direction.

The foregoing detailed description has vclaims should be construed as broadly as permissible in view of the prior art.

1. -A jack comprising, a hollow casing, a drive nut rotatably mounted therein, a Sleeve slidably keyed to said nut, said sleevebeing provided interiorly with upper and lower nuts, a hollow liftingV screw engaging said upper nut, a rotatably mounted screw post lengaging said lower nut, and means for restraining rotation of said screw post.

2. A jack comprising, a hollow casing, a drive nut rotatably mounted in said casing, a sleeve member slidably keyed to said nut, said sleeve being provided interiorly with upper and lower threaded portions, a lifting screw engaging 'said upper threaded portion, arotatably mounted screw postengaging said lower threaded portion, and means for In one case, frictional means is employed to'A retard rotation whileV in theV other case positive means are provided 'i to prevent rotation of the screw except when ids iio

restraining rotation of said screw post during vertical movement of said Sleeve.

3. A jack comprising, a hollow casing, an annular drive nut mounted therein, a sleeve slidably mounted in said casing and connected to said nut, said sleeve being provided interiorly with upper and lower nuts, a hollow lifting screw engaging said upper nut, a screw post rotatably mounted in said casing and engaging said lower nut, means for retaining rotation of said screw post until said sleeve reaches the limits of its travel, and means for actuating said drive nut.

4. In a screw ack provided with a hollow casing and a drive nut mounted therein, a rotatable screw post supported in said casing, a pair of threadedly connected and telescoping lifting members, one of said members being threadedly connected with said screw post, and means for restraining the rotation of said screw post.

5. A screw jack comprising, a hollow casing, a disk rotatably mounted in said casing, a screw post iixed to said disk, means for exerting friction against said disk, an annular nut carried by said casing, a sleeve member extending through said nut and slidably keyed thereto, said sleeve member being threadedly connected to said screw post, and a hollow lifting screw encircling said screw post, and threadedly engaging said sleeve member.

6. A screw jack comprising, a hollow casing, a screw post rotatably mounted therein, means for exerting friction upon said screw post, nested lifting members encircling said screw post, one of said members being threadedly connected therewith, and means for rotating one of said nested lifting members.

7 A screw jack comprising, a hollow casing, a disk rotatably mounted in the bottom of said casing, a spring-urged plunger engagingtheperipheryof said disk, a screw post fixed to said disk and extending upwardly through said casing, a sleeve member provided with a nut engaging said screw post, a hollow lifting screw threadedly engaging said sleeve, a nut rotatably mounted in said casing and keyed to said sleeve, and means for actuating said nut.

V8. A screw jack comprising, a hollow casing, an inner screw rotatably mounted therein, means for yieldably retarding the rotation o-f said inner screw, a sleeve member equipped with a nut engaging said inner screw, a lifting screw threadedly engaging said sleeve member, stop means carried by said inner screw and adapted to engage said sleeve nut, and means for rotating said sleeve.

9. A screw jack comprising, a hollow casing, a screw post rotatably mounted therein, a lifting member threadedly engaging said post, and cooperating means in said 4casing and associated-with said post for preventing rotation of said post 4except when said lifting member reaches the limit of `its vertical travel.

y 10. A screw jack comprising, a hollow casing, a screw post rotatably mounted therein, a sleeve member threadedly engaging said post, a lifting screw in threaded relation with said sleeve, and positive means for preventing rotation of said screw post until said sleeve reaches the limit of its vertical travel.

11. Ajackcomprising, a hollow casing having a vertical groove in the walls of thebore,V the ends of the bore being larger in diameterthan the main borea screw post rotatably mounted in said casing, and having a vertical k groove, a sleeve member equipped interiorly with upper' and lower` nuts, said lower nut being in engagement with said screw post, a lifting screw engaging said upper nut, and locking means carried by said sleeve member and equipped with a lug engaging the groove of said screw post and with a lug engaging the vertical groove in the wall of the casing to prevent rotation of said screw post except when said second-mentioned lug reaches the enlargements at the ends of the bore.

l2. A jack comprising, a hollow casing having a vertical bore and a vertical groove therein, one end of the bore rbeing of larger diameter than the main bore and` provided with cam shoulders joining the enlargement with the walls of the groove, a screw post rotatably mounted in said casing and provided with a vertical groove, a sleeve threadedly engaging said screw post, and a locking member carried by said sleeve and provided with projections engaging the groove of said screw post and the groove of said casing.

13. A screw jack comprising, a hollow casing having a vertical groove in the walls of the bore and an enlargement in the base of the casing communicating with said groove, a screw post rotatably mounted in said casing, a lifting member threadedly engaging said post, said post being provided with a vertical groove, a locking member carried by said lifting member and equipped with lugs engaging the groove of said post and the groove of said casing, and a spring mounted in the base of said bore and adapted to urge said locking `member in an upward direction.

14. A jack comprising, a hollow casing providedwith a vertical groove and an enlargement in the base of the casing communicating with said groove, said groove being provided with a cam shoulder connecting said .enlargement with a wall of said groove, a

screw post rotatably mounted in said casing and provided with a vertical groove, a lifting member in threaded engagement with said screw post, a lifting screw in threaded relation with said lifting member, a locking member carried by said lifting member and provided with projections engaging the groove of said post and the groove of said casing, and a spring in the base of said casing and adapted to urge said locking member toward said cam shoulder.

15. A jack comprising, a, hollow casing equipped with a plurality of vertical grooves and enlargements at the ends of the casing communicating with the grooves, a screw post rotatably mounted in the casing and provided with a vertical groove, `a sleeve member equipped With upper and lowerknuts, said lower nut engaging said screw post, a lifting screw engaging said upper nut, and a. looking washer carried by said sleeve member and provided with projections engaging the groove of said post and the grooves of said casing.

WiLLrAM o. TYLER. 

